Abstract
Supramolecular polymers are fascinating materials capable of displaying unique stimuliresponsive properties. Despite recent advances, including the development of living supramolecular polymerisation methods, these dynamic materials remain challenging to control.Perylene diimides are exemplary functional dye molecules, with a wide range of potential applications from pigments to organic photovoltaics. Supramolecular polymerisation of perylene diimides
allows optimisation of their optoelectronic properties, whilst concurrently giving detailed insights
into the polymerisation process.
The majority of the work described in this thesis focuses on the development of methodologies
to control the supramolecular polymerisation of perylene diimide derivatives. Firstly, the range
of structures accessible through living supramolecular polymerisation of a family of amphiphilic
perylene diimides is investigated. A novel method of tuning solvent composition and monomer
concentration in conjunction with living supramolecular polymerisation allowed the formation of
2D structures with precisely and independently tuned dimensions. Further solvent optimisation
facilitated the formation of triblock supramolecular copolymers with controllable block lengths.
Heteroatom substitution has been reported to be a facile process to tune the optoelectronic
properties of perylene diimides. In this thesis, the effects of thionation of imide functionalities on
the supramolecular polymerisation process are explored. In addition to optical changes, successive
degrees of thionation are found to result in a gradual mechanistic transition from cooperative to
isodesmic. Significant morphological effects are also noted, with nanofibres, nanoribbons, sheets,
and nanoparticles all accessible, realising a new route towards the control of the supramolecular
structures formed by perylene diimides.
A synergistic use of covalent cross-linking alongside the described methods of controlling
supramolecular polymerisation shows promise for the formation of more complex supramolecular
structures. Incorporation of an alkene-capped monomer allowed structural fixing to improve
thermal and solvent stability of the self-assemblies, and the kinetic stability of seed nanofibres.
Selective cross-linking of the aforementioned block copolymers allows clear visualisation and
confirmation of their segmented nature. This strategy should be widely applicable, as it involves
only a minor structural modification to the monomer.
Overall, the strategies detailed in this thesis offer opportunities to create organic self-assembled nanostructures with exceptional control. Further development in these areas should allow
the tuning of these constructs and their physical and optoelectronic properties, for a variety of
potential applications.
| Date of Award | 11 May 2021 |
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| Original language | English |
| Awarding Institution |
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| Supervisor | Charl F J Faul (Supervisor) |